Navigation system and controlling method for the motor vehicle

ABSTRACT

A navigation system ( 20 ) includes a transceiver unit ( 210 ), a display unit ( 250 ), an input unit ( 260 ) and an ECU ( 230 ). The transceiver unit ( 210 ) transmits a signal for demanding a detection of a navigation path to a path detecting server ( 10 ) and then receives path data which represent the navigation path from the path detecting server ( 10 ). The display unit ( 250 ) outputs the navigation path or a revised navigation path. The ECU ( 230 ) conveys data on a departure point and a destination from the input unit ( 260 ) to the transceiver unit ( 210 ) and transfers the path data from the transceiver unit ( 210 ) to the display unit ( 250 ). Further, the ECU ( 270 ) precalculates deviation-expected paths in the course of driving along the navigation path and selects the revised navigation path among the precalculated deviation-expected paths in case a present position of a mobile object deviates form the navigation path to thereby provide the revised navigation path to the display unit ( 250 ).

TECHNICAL FIELD

The present invention relates to a navigation system and a method forcontrolling same; and, more particularly, to the navigation system andthe method for controlling same, which informs a driver in a vehicle ofa rerouted navigation path in case the vehicle deviates from anavigation path.

BACKGROUND OF THE INVENTION

Conventional navigation systems are usually mounted in mobile objectssuch as a vehicle, a vessel, an airplane and the like, so as to detect acurrent position, a proceeding direction and a speed thereof.

The conventional navigation system detects the current position of amobile object based on GPS (global positioning system) signalsindicating information on longitude, latitude, and altitude thereof,which are received from a plurality of satellites, and displays thedetected current position of the object on a map visualized through adisplay device. The navigation system also searches for a navigationpath, i.e., a short-cut path or an optimum path from a departure pointto a destination, and display the navigation path on the map visualizedthrough the display device.

FIG. 1 is a flow chart showing a conventional method for controlling anavigation system. In case a vehicle deviates from a navigation path,the navigation system operates as follows.

After the navigation system receives a command signal to detect anavigation path, the signal being inputted by a driver, the navigationsystem transmits the signal to a path detecting server via a wirelessnetwork (S 10). Then, the path detecting server figures out thenavigation path by using a route planning method to thereby provide pathdata, which represents the navigation path, to the navigation system viathe wireless network (S 20).

The navigation system displays the navigation path on a screen such asan LCD and the like in response to the path data (S 30).

A navigation sensor unit included in the navigation system detects apresent position of the vehicle in the course of displaying thenavigation path (S 40).

The navigation system determines whether the present position of thevehicle deviates from the navigation path or not (S 50). When thepresent position of the vehicle deviates from the navigation path, thenavigation system sends a signal demanding a detection of a revisednavigation path to the path detecting server (S 60).

Subsequently, the path detecting server figures out the revisednavigation path required by the navigation system. Herein, the revisednavigation path means a new navigation path from a deviation point tothe destination (S 70), wherein the deviation point is a place where thevehicle begins to deviate from the navigation path.

Thereafter, the path detecting server transmits revised path data, whichindicates the revised navigation path, to the navigation system via thewireless network. Then, the navigation system displays the revisednavigation path in response to the revised path data (S 30).

However, in step 50, if the vehicle is determined to continue to travelalong the original navigation path, the navigation system determineswhether the vehicle has arrived at the destination or not (S 80).

If the vehicle has arrived at the destination, the operation of thenavigation system is completed (S 90); otherwise, the navigation systemreturns to step 30 to display the navigation path.

As mentioned above, when the vehicle deviates from the originalnavigation path, the conventional navigation system does not inform thedriver of a revised navigation path until the navigation system demandsa detection of the revised navigation path to the path detecting serverand then receives the revised path data from the path detecting server.Therefore, there is a time delay problem in finding the revisednavigation path.

SUMMARY OF THE INVENTION

It is, therefore, a primary object of the present invention to provide anavigation system and a method for controlling same which informs adriver in a vehicle of a revised navigation path, which has beenprecalculated, in case the vehicle deviates from an original navigationpath so that a time delay required to acquire the revised navigationpath is greatly reduced.

In accordance with one aspect of the present invention, there isprovided a navigation system for use in a mobile object, including: atransceiver unit for transmitting a signal for demanding a detection ofa navigation path, which is a short-cut path or an optimum path from adeparture point to a destination, to a path detecting server via awireless network and then receiving path data which represents thenavigation path from the path detecting server via the wireless network;a display unit for outputting the navigation path or a revisednavigation path; an input unit for inputting data on the departure pointand the destination; and an ECU for transferring the data on thedeparture point and the destination from the input unit to thetransceiver unit, transferring the path data from the transceiver unitto the display unit, precalculating deviation-expected path data whichrepresent deviation-expected paths in the course of driving along thenavigation path, and selecting revised path data which represent therevised navigation path, among the precalculated deviation-expected pathdata in case a present position of the mobile object deviates from thenavigation path to thereby provide the revised navigation path to thedisplay unit.

In accordance with another aspect of the present invention, there isprovided a method for navigating a mobile object traveling from adeparture point to a destination, including the steps of: (a)transmitting a signal for demanding a detection of a navigation path,which is a short-cut path or an optimum path from the departure point tothe destination, to a path detecting server via a wireless network; (b)receiving path data which represent the navigation path from the pathdetecting server via the wireless network; (c) displaying the navigationpath in response to the received path data; (d) precalculatingdeviation-expected path data which represent deviation-expected paths;(e) selecting revised path data, which represent a revised navigationpath, among the precalculated deviation-expected path data in case apresent position of the mobile object deviates from the navigation path;and (f) displaying the revised navigation path in response to therevised path data.

BRIEF DESCRIPTION OF DRAWINGS

The above and other objects and features of the present invention willbecome apparent from the following description of preferred embodiments,given in conjunction with the following drawings, in which:

FIG. 1 is a flow chart showing a conventional method for controlling anavigation system;

FIG. 2 shows a structure of a navigation system in accordance with apreferred embodiment of the present invention;

FIG. 3 represents a flow chart showing a method for controlling thenavigation system in accordance with the preferred embodiment of thepresent invention;

FIG. 4 describes a navigation path generated in accordance with thepreferred embodiment of present invention; and

FIGS. 5A to 5C provide a procedure of displaying a revised navigationpath, which has been precalculated in case a vehicle deviates from theoriginal navigation path in accordance with the preferred embodiment ofpresent invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 2 shows a structure of a navigation system in accordance with apreferred embodiment of the present invention. The navigation system maybe installed in a mobile object such as an automobile. As shown in FIG.2, the navigation system includes a path detecting server 10, anavigation system 20 and a wireless network 30.

The navigation system 20 includes a transceiver unit 210, a navigationsensor unit 220, an ECU (electronic control unit) 230, an audioprocessing unit 240, an image processing unit 250, an input unit 260 anda memory 270.

Initially, a driver inputs to the navigation system 20 data on adeparture point and a destination through the input unit 260 and/or theaudio processing unit 240. Then, the ECU 230 transmits the data from theinput unit 260 or the audio processing unit 240 to the transceiver unit210. After the transceiver unit 210 receives the data, the transceiverunit 210 transmits the data and a signal for demanding a detection of anavigation path to the path detecting server 10 via the wireless network30. The navigation path represents a short-cut path or an optimum pathfrom the departure point to the destination. The path detecting server10 begins to detect the navigation path in response to the signal. Afterthe navigation path is detected, the path detecting server 10 transmitspath data representing the navigation path to the transceiver unit 210via the wireless network 30. Thereafter, the ECU 230 transmits the pathdata from transceiver unit 210 to the audio processing unit 240 and/orthe image processing unit 250.

In the meantime, the navigation sensor unit 220 measures a presentposition of the vehicle. And then the navigation sensor unit 220transmits data representing the measured present position of the vehicleto the ECU 230 when the data is demanded by the ECU 230. The navigationsensor unit 220 includes a GPS receiver for receiving GPS signals and aplurality of sensors for perceiving a rotational motion and a speed ofthe vehicle.

The audio processing unit 240 receives the path data from the ECU 230and then outputs the path data in the form of an audio signal. On theother hand, the audio processing unit 240 can be served as an inputdevice. That is, the driver can input the data on the departure pointand the destination through the audio processing unit 240 in the form ofthe audio signal, i.e., the voice of the driver.

The image processing unit 250 displays the navigation path and thepresent position of the vehicle on a map which is displayed on a screensuch as an LCD and the like.

The input unit 260 transmits the data of the departure point and thedestination, which are inputted therethrough by the driver, to the ECU230.

The memory 270 stores the path data or deviation-expected path datawhich are received through the transceiver unit 210 via the ECU 230.Herein, the deviation-expected path data represent new navigation pathsfrom optional deviation points to the destination. Moreover, thedeviation-expected paths are precalculated in the course of travelingalong the original navigation path. The memory 270 transmits the storedpath data (or the deviation-expected path data) to the ECU 230 when theECU 230 requests the data in order to display the data through the audioprocessing unit 240 and/or the image processing unit 250.

The ECU 230 displays the path data through the audio processing unit 240and/or the image processing unit 250 in case the vehicle proceeds alongthe original navigation path. Meanwhile, the ECU 230 precalculates thedeviation-expected path data by using the path data and a map structurecomprising links, nodes and the like. Thereafter, the ECU 230 stores thedeviation-expected path data in the memory 270. Moreover, the ECU 230determines whether or not the present position of the vehicle calculatedby the navigation sensor unit 220 is located on the original navigationpath. In case the present position of the vehicle deviates from thenavigation path, the ECU 230 immediately sends a signal to demand theaudio processing unit 240 or the image processing unit 250 to display arevised navigation path which is selected among the deviation-expectedpaths by inspecting which of the deviation-expected paths includes thepresent position of the vehicle. The revised navigation-path representsa new navigation path from a deviation point to the destination. Thedeviation point is the place where the vehicle begins to deviate fromthe navigation path.

FIG. 3 shows a flow chart showing a method for controlling thenavigation system in accordance with the preferred embodiment of thepresent invention. With reference to FIGS. 2 and 3, the method forcontrolling the navigation system will be described in detail.

First, the driver inputs data on the departure point and the destinationby using the input unit 260 and/or the audio processing unit 240. Thedata are transmitted to the transceiver unit 210 via the ECU 230.Thereafter, the transceiver unit 210 sends a signal for demanding adetection of a navigation path to the path detecting server 10 via thewireless network 30 (S 100).

And then, the path detecting server 10 calculates the navigation path,i.e., a short-cut path or an optimum path from the departure point tothe destination, to thereby provide path data, which represents thenavigation path, to the transceiver unit 210 via the wireless network 30(S 110).

The transceiver unit 210 transmits the path data to the ECU 230, whichthen stores the path data in the memory 270 and orders the imageprocessing unit 250 and/or the audio processing unit 240 to display thepresent position of the vehicle and the navigation path (S 120).

In the course of displaying the navigation path, deviation-expected pathdata are precalculated by the ECU 230. The ECU 230 stores thedeviation-expected path data in the memory 270 (S 130).

Meanwhile, the navigation system 20 detects the present position of thevehicle through the navigation sensor unit 220 (S 140).

The ECU 230 determines whether the present position of the vehicledeviates from the navigation path or not (S 150). When the presentposition of the vehicle deviates from the navigation path, the ECU 230displays a revised navigation path through the audio processing unit 240and/or the image processing unit 250 (S 160).

Either in case the present position of the vehicle does not deviate fromthe navigation path at the step 150 or in case the revised navigationpath is displayed at the step 160, the ECU 230 determines whether or notthe present position of the vehicle reaches the destination (S 170).

In case the present position of the vehicle reaches at the destination,an operation of the navigation system is completed (S 180). Otherwise,the ECU 230 performs again the step 120 to display the navigation pathor the revised navigation path.

FIG. 4 depicts exemplary navigation path generated by using the methodin accordance with the present invention. As shown in FIG. 4, thenavigation path is displayed on the screen by using thick lines drawn torepresent links #1 to #4. The navigation path is composed of nodes suchas A1, A2 and the like and links which are lines between the nodes.

There is no need to calculate the revised navigation path when thevehicle deviates from the navigation path. Since the deviation-expectedpaths are precalculated while the mobile object traveling along thenavigation path, the navigation system 20 may display the revisednavigation path immediately after the vehicle deviates from thenavigation path. Herein, the deviation-expected paths are totallyprecalculated from optional points, selected among all the nodes and thelinks between the present position and the destination, to thedestination. Therefore, in case the vehicle deviates from the navigationpath at the deviation point, the revised navigation path is selectedamong the deviation-expected paths by inspecting which of thedeviation-expected paths includes the present position of the vehicle.And then the revised navigation path is displayed from the deviationpoint to the destination immediately.

FIGS. 5A to 5C show a procedure of displaying the revised navigationpath in case the vehicle deviates from the navigation path in accordancewith the preferred embodiment of the present invention.

For example, suppose that the navigation path is displayed as shown inFIG. 4. The navigation path from a node 40, i.e., the departure point,to a node 60, i.e., the destination, includes the link #1, the node A1,the link #2, the node A2, the link #3, the node A3 and the link #4. Incase the present position of the vehicle 50 is located on the link #1 asshown in FIG. 5A, the navigation system 20 guides the driver to followthe path data P, i.e., to enter the link #2, at the node A1.

However, in case the vehicle 50 deviates from the path data P byentering the link #5 as shown in FIG. 5B, the navigation system 20displays the revised navigation path Pn from the link #5 to thedestination (i.e., the link #5, the node A4, the link #6, the node A5,the link #7, the node A2, the link #3, the node A3, the link #4),immediately, because all the deviation-expected paths have beenprecalculated from the node A1 to the destination at the time while thevehicle travels along the link #1.

As described above, the navigation system and method in accordance withthe present invention reduce a time delay which is required to acquire arevised navigation path by displaying the revised navigation path to thedriver right after the vehicle deviates from the navigation path.

While the invention has been shown and described with respect to thepreferred embodiments, it will be understood by those skilled in the artthat various changes and modifications may be made without departingfrom the spirit and scope of the invention as defined in the followingclaims.

1. A navigation system for use in a mobile object, comprising: atransceiver unit for transmitting a signal for demanding a detection ofa navigation path, which is a short-cut path or an optimum path from adeparture point to a destination, to a path detecting server via awireless network and then receiving path data which represents thenavigation path from the path detecting server via the wireless network;a display unit for outputting the navigation path or a revisednavigation path; an input unit for inputting data on the departure pointand the destination; and an ECU for transferring the data on thedeparture point and the destination from the input unit to thetransceiver unit, transferring the path data from the transceiver unitto the display unit, precalculating deviation-expected path data whichrepresent deviation-expected paths in the course of driving along thenavigation path, and selecting revised path data which represent therevised navigation path, among the precalculated deviation-expected pathdata in case a present position of the mobile object deviates from thenavigation path to thereby provide the revised navigation path to thedisplay unit.
 2. The system of claim 1, further comprising a navigationsensor unit for detecting the present position of the mobile object. 3.The system of claim 2, wherein the display unit includes an audioprocessing unit for outputting the path data or the revised path data inthe form of an audio signal and/or an image processing unit foroutputting the path data or the revised path data in the form of animage signal.
 4. The system of claim 3, wherein the ECU selects therevised path data among the deviation-expected path data by inspectingwhich of the deviation-expected paths includes the present position. 5.The system of claim 1, further comprising a memory for storing the pathdata and the deviation-expected path data which are transmitted from theECU and transmitting the stored path data and the storeddeviation-expected path data in case the ECU requires for the storedpath data and the stored deviation-expected path data to display thestored path data and the stored deviation-expected path data through thedisplay unit.
 6. The system of claim 1, wherein the deviation-expectedpaths are precalculated from a plurality of deviation points to thedestination, the deviation points being arbitrary places where themobile object begins to deviate from the navigation path.
 7. A methodfor navigating a mobile object traveling from a departure point to adestination, comprising the steps of: (a) transmitting a signal fordemanding a detection of a navigation path, which is a short-cut path oran optimum path from the departure point to the destination, to a pathdetecting server via a wireless network; (b) receiving path data whichrepresent the navigation path from the path detecting server via thewireless network; (c) displaying the navigation path in response to thereceived path data; (d) precalculating deviation-expected path datawhich represent deviation-expected paths; (e) selecting revised pathdata, which represent a revised navigation path, among the precalculateddeviation-expected path data in case a present position of the mobileobject deviates from the navigation path; and (f) displaying the revisednavigation path in response to the revised path data.
 8. The method ofclaim 7, further comprising a step of detecting the present position ofthe mobile object.
 9. The method of claim 8, wherein the navigation pathand the revised navigation path are outputted either in the form of anaudio signal or in the form of an image signal at steps (c) and (f). 10.The method of claim 9, wherein the revised path data are selected amongthe deviation-expected path data by inspecting which of thedeviation-expected paths includes the present position at step (e). 11.The method of claim 7, further comprising the steps of storing the pathdata or the deviation-expected path data in a memory after the path dataor the deviation-expected path data are received and retrieving thestored path data or the stored deviation-expected path data from thememory while displaying the navigation path or the revised navigationpath.
 12. The method of claim 7, wherein the deviation-expected pathsare precalculated from a plurality of deviation points to thedestination at the step (d), the deviation points being arbitrary placeswhere the mobile object begins to deviate from the navigation path.